1. Technical Field
The present invention relates to map-reading navigational aids and in particular to a stereo micrographic map-reader with a built-in compass, protractor and internal light source wherein the casing for the map-reader is completely light-tight.
2. Background Art
Maps are generally printed on large cumbersome sheets of paper which must be folded in an ornate fashion for relatively compact storage. Trying to read such a map outdoors in the wind represents a considerable nuisance, and trying to read a large map in a confined space, such as a vehicle represents another difficult problem in trying to spread the map out. Reading printed maps at night requires a substantial amount of light directed on the map, which interferes with pilots or drivers beside the map reader and reveal the user's position in hunting or combat.
Maps are two dimensional and do not give a sense of depth to the landscape being studied. Contour lines must be relied upon to give some idea of elevational differences.
To establish direction and orientation, it is necessary to use a map with a separate compass, use the compass to establish the magnetic North, and then find North on the map and orient the map accordingly with an allowance for the difference between true North and magnetic North.
To determine distances with a map it is necessary to use a separate protractor or other measuring instrument applied to the map taking the scale of the map into consideration.
Other lighted viewing devices do not provide safety in that the light is always visible through loading slots and around the eyepiece.